Installing RDQM (replicated data queue managers)

Installation tasks associated with RDQM are grouped in this section. RDQM is available on x86-64 for RHEL 8 (8.8 or later) and RHEL 9 (9.2 or later).

Before you begin

RDQM requires that the mqm user has the same UID on each node and that the mqm group has the same GID on each node. You should create the mqm IDs before running the installation procedure, using the groupadd and useradd commands to set the UID and GID the same on each node. See Setting up the user and group on Linux.

Pacemaker is one of the prerequisites for RDQM. Pacemaker requires that certain Linux packages are installed on the system. The list for supported levels of RHEL 8 and RHEL 9 assumes that a minimal set of system packages has been installed that includes the mandatory and default packages from the mandatory groups of the Server environment group.

The prerequisites for supported levels of RHEL 8 (Pacemaker 2) are:

cifs-utils
libtool-ltdl
libxslt
net-snmp-libs
nfs-utils
perl-TimeDate
psmisc
python36
python3-lxml

The prerequisites for supported levels of RHEL 9 (Pacemaker 2) are:

libxslt
net-snmp-libs
nfs-utils
nfs-utils-coreos
perl-TimeDate
python3-lxml
python-unversioned-command

Additional prerequisites for installing the drbd-selinux package on SELinux are as follows:

selinux-policy
selinux-policy-base
rpm-plugin-selinux
selinux-policy-targeted

These packages in turn have their own requirements (which are not listed here). When Pacemaker is installed, it reports any missing packages that also need to be installed before installation can complete successfully.

Note: The Pacemaker component of RDQM requires a user named hacluster and a group named haclient. By default, these use a uid and gid of 189, although it is possible to specify a different uid and gid if required. The installation of Pacemaker creates the user and group if they do not exist.

About this task

To install support for RDQM (replicated data queue managers), you complete the following tasks:

Install DRBD on each node.
Install Pacemaker on each node.
Install IBM MQ on each node.
Install RDQM on each node.

The DRBD and Pacemaker RPM packages are supplied on the IBM MQ media. You should install the versions supplied with IBM MQ. Do not download your own versions, and you should ensure that the install does not pick up any other versions of these packages that you already have on your system.

To ensure that the packages supplied with RDQM are used, add exclude lines to the definition of any yum repository that could supply alternatives, such as the AppStream repository in RHEL 8. The exclude line needs to be applied to any yum repository defined on the system that could supply the standard RHEL alternative to any of the packages supplied with IBM MQ.

For example, for RHEL 8 use the following exclude line:

exclude=cluster* corosync* drbd kmod-drbd libqb* pacemaker* resource-agents* ktls-utils*

For example, for RHEL 9 use the following exclude line:

exclude=cluster* corosync* crm* libknet* libnozzle* libqb* pacemaker* python3-parallax* resource-agents* ktls-utils*

For supported levels of RHEL 8, components are found under the Advanced/RDQM/PreReqs/el8/ directory. For supported levels of RHEL 9, components are found under the Advanced/RDQM/PreReqs/el9/ directory.

Attention: If you are using UEFI secure boot, you might need to enroll the key for the DRBD kernel module. See https://linbit.com/drbd-user-guide/drbd-guide-9_0-en/#s-linbit-packages. If UEFI secure boot is in use and the key is not enrolled, you will see the following error message.

modprobe: ERROR: could not insert 'drbd': Required key not available

The DRBD and Pacemaker packages are signed with the LINBIT GPG key. Use the following steps to download and import the public LINBIT GPG key:

Download the linbit-keyring package for your operating system version from https://packages.linbit.com/public/linbit-keyring/.
Issue the following command to install the linbit-keyring package:
```
rpm -i linbit-keyring.rpm
```
Issue the following command to import the LINBIT signing key:
```
rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-linbit
```

Without this step, an RPM install of these packages issues the following warnings:

warning: rpm-name: Header V4 RSA/SHA512 Signature, key ID b826fe48: NOKEY

You can have multiple IBM MQ installations on each server, but only one of these installations should be an RDQM installation (see Installing RDQM alongside other IBM MQ installations). You can install the IBM MQ components in a custom location, if required, see Installing RDQM to a non-default location.

Attention: You should retain the installation media, in case there is a need to revert to this level, after upgrading to a later level.

Procedure

Complete the following steps on each node:

Log in as root, or switch to the root user by using the su or su - commands. Alternatively, you can use the sudo command to run commands as the root user, if your system administrator gave you the privilege to do so.

To use the sudo command, add sudo before the command that you want to run. For more information about the su and sudo commands, see Exploring the differences between sudo and su commands in Linux on the Red Hat® website.
Change into the directory containing the installation image.
Determine which DRBD kernel module is needed for the system on which RDQM is being installed. See https://ibm.biz/mqrdqmkernelmods for up-to-date kernel module information. Helper scripts are provided in the kmod-drbd-9 directories. For example, on a RHEL 8.10 system, running the helper script Advanced/RDQM/PreReqs/el8/kmod-drbd-9/modver returns the following information, identifying the kernel module that you need to install:
```
kmod-drbd-9.0.23_4.18.0-553-1.x86_64.rpm
```
Install the appropriate DRBD kernel module that you identified in step 1. For example, for RHEL 8.10 you run the following command:
```
dnf install Advanced/RDQM/PreReqs/el8/kmod-drbd-9/kmod-drbd-9.0.23_4.18.0-553-1.x86_64.rpm
```
Install the required DRBD utilities. For example, for RHEL 8.10 you run the following command:
```
dnf install Advanced/RDQM/PreReqs/el8/drbd-utils-9/*
```
Install Pacemaker. For example, for RHEL 8.10 you run the following command:
```
dnf install Advanced/RDQM/PreReqs/el8/pacemaker-2/*
```
The Pacemaker installer reports any missing packages that also need to be installed before the install can complete successfully.
Accept the IBM MQ license:
```
./mqlicense.sh
```
Install IBM MQ. This is like a standard IBM MQ install. At the minimum, you must install the following:
```
dnf install MQSeriesGSKit* MQSeriesServer* MQSeriesRuntime*
```
Install RDQM:
```
dnf install Advanced/RDQM/MQSeriesRDQM*
```

What to do next

You can now configure the Pacemaker cluster and replicated data queue managers, or you can configure disaster recovery replicated data queue managers. See RDQM high availability or RDQM disaster recovery.